1. Technical Field
The present invention relates to a motor-fastening mechanism and a cam device.
2. Related Art
Regarding a method for fastening to an input shaft of a driven member an output shaft of a motor which rotates with high precision such as a servo motor, what is conventionally adopted is a method for fastening an output shaft to an input shaft by a coupling. If an output shaft is fastened to an input shaft by a coupling, it is necessary to absorb misalignment such as a parallel error, an angle error, and an axial error which occur on a fastened portion where the output shaft and the input shaft are fastened to each other. Therefore, an elastic coupling such as a rubber resin coupling, a bellows coupling, a metal coil spring coupling, and a metal plate spring coupling is used, and such misalignment is absorbed by elastic deformation of the elastic coupling (see “Coupling”, Kikai Sekkei (Mechanical Design), Jan. 1, 1997, vol. 41, no. 1, p. 60-64).
The above-mentioned elastic coupling is effective in absorbing misalignment. However, since misalignment is absorbed by elastic deformation of the elastic coupling, transfer stiffness deteriorates and an angle of rotation of a motor is absorbed. As a result thereof, a runout error occurs. Further, it causes a problem that misalignment tends to occur.